Our objectives are to control growth of neoplastic cells and/or regression of tumors using lipid "analogue" compounds at concentrations non-toxic to normal mammalian cells. Studies of this nature were to be run in vivo and in vitro. These compounds are postulated to block the formation of certain glycolipids and neutral lipids (alkyl diacyl glycerides) which can change the functional aspects of macromolecular structures of the cell such as plasma membranes, microsomes, etc. Normal and tumorigenic cells cultivated in vitro will be treated with lipid isomers to find compounds that alter the tumorigenic properties of cells in mice and cell culture. Lipid analysis and lipid metabolism will be compared in different neoplastic cells under treatment with labeled and "cold" lipid isomers in whole cells and macromolecular structures of these cells. Treated tumorigenic cells will be transplanted into mice to observe whether tumor inhibition occurs. Mice producing spontaneous tumors or already having tumors will be treated with the lipid isomers in order to inhibit tumor growth. Radioisotope tracer and electron microscopy-radioautography studies will be performed to follow mode and site of action of the lipid compounds which inhibit or prevent tumor growth. After successful results have been obtained inhibiting growth of tumorigenic cells in cell culture with lipid isomers, treatment of tumors spontaneously arising in mice will be attempted, as well as inhibition of tumor growth that could occur in the same mice. Human cancer tissue will be separated into single cells, treated and transplanted into mice to observe for loss of tumorigenicity after treatment. Appropriate controls of untreated cells from tumor tissues will be transplanted into mice to be sure the cells are tumorigenic.